A boot is attached, to a constant velocity universal joint used for transmission of power in an automobile or various industrial machines, in order to prevent foreign matter such as dust from entering the inside of the joint and to prevent leakage of grease sealed in the joint. As materials of the boot for a constant velocity universal joint, a silicone material a CR material (chloroprene), a VAMAC material (ethylene-acrylic rubber), a CM material (chlorinated polyethylene), and the like are known.
The boot for the constant velocity universal joint is mounted and fixed to the constant velocity universal joint by using a fastening band. An example of the band is a low-profile band described in Patent literature 1 or the like. This band is configured by rolling a belt-shaped member 1 as illustrated in FIG. 17 into a ring shape as illustrated in FIGS. 18A, 18B, and 18C. The band is externally fitted to and mounted on a mounting portion of the boot.
On one end side of the belt-shaped member 1, a protrusion portion 2 protruding toward a front surface side, a claw portion 3 located close to the protrusion portion 2, and protrusion, portions 4, 5 located close to the claw portion 3 and protruding toward the front, surface side are provided. On the other end side of the belt-shaped member 1, an engaging hole 6 having a rectangular shape and an elongated hole 7 located close to the engaging hole 6 are provided. In addition, the elongated hole 7 is provided with a protrusion portion 8 that protrudes toward the front surface side on the side opposite to the engaging hole 8.
In a method of fixing the boot using this band, first, the band is rounded into a ring shape so that the protrusion portion 2 fits in the elongated hole 7 as illustrated in FIG. 18A. That is, a ring portion 9 is formed, and the ring portion 9 is externally fitted to a band mounting portion of the boot in a loosely fitted state. In this case, the protrusion portion 2 is placed on a side closer to the engaging hole 6 in the elongated hole 7.
Thereafter, the protrusion portion 8 and the protrusion portion 2 are sandwiched by a tool 10 (see FIGS. 19A and 19B) to be described later, and the tool 10 is operated to bring the protrusion portion 2 and the protrusion portion 8 relatively closer to each other as illustrated in FIG. 18B. As a result, the diameter of the ring portion 9 gradually decreases. Then, as illustrated in FIG. 18C, in a state where the protrusion portion 2 and the protrusion portion 8 are in contact with each other, the protrusion portion 5 is engaged with the engaging hole 6, and the protrusion portion 4 is engaged with the side closer to the engaging hole 6 of the elongated hole 7. As a result, this band clamps the band mounting portion of the boot. Therefore, the boot can be fixed to an outer joint member of the constant velocity universal joint or a shaft fitted into an inner joint member of the constant velocity universal joint.